Form tool chip breaker generating fixture



Aug. 13, 1946. w. F. ROSS FORM TOOL CHIP BREAKER GENERATING FIXTURE Filed Aug. 17, 1944 2 Sheets-Sheet l IN VEN TOR. "(Wm/VJ GEM.

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m m 9!? 1 R Patented Aug. 13, 19 46 i 7 FORM TOOL CHIP B REAKER GEN ERATING FIXTURE "Walter F. Ross, Detroit, Mich; assignor to Motor 1 Tool Manufacturing Company, Detroit, Mich, a corporation of Michigan Application August 17, 1944,'Serial No. 549,891

2 Claims.

.This invention relates to mechanism for the grinding of chip breaker interruptions inthe cutting teeth of rotary form tools, and similar tools having profiled outlines of varying diameter throughout the length thereof, and has for its object to provide an arrangement which is readily adaptable to produce this operation quickly and accurately on different shapes and sizes of tools without calling for tedious and critical settingup of the work. v

A still further object is to provide such a mechanism of simple and easily constructed form which maybe readily attached as a fixture to an existing grinding machine.

A still further object is to provide in such mechanism for the simple coupling of the work to a follower finger, co-acting with a dummy or profiled stop defining the envelope of the work, in such manner that the rotation of the work will be accompanied by the traverse of the follower finger over a line defining the contour of the dummy and such traverse translated into movement of the work relative to the grinding wheel along such defined path. 4

Still further, objects or advantages additional or subsidiary to the aforesaid objects, or resulting from the construction or operation of the invention as it may be carried into efiect, will be ample, having reference to the accompanying drawings, wherein: 1

, Figure 1 is a plan of a fixture'embodying the said invention;

Figure 2 is a longitudinal vertical section taken on plane indicated by the line 22 in Figure 1; and I come apparent as the said invention is hereinafter further disclosed.

In carrying. the said invention into efiect, I may provide a transversely slidable table mounted on a longitudinal movable table which in turn with said dummy and carried by a rider bar supported by said fixed structure, means biasing said transversely slidable table to maintain said dummy in contact with said follower finger during longitudinal movements of said correspondingly movable table; a hand operated lead screw linked to said fixed follower finger, whereby the longitudinal movement of the dummy may be effected, and means transmitting rotary motion of said feed screw to the work, whereby the said work may be rotated in contact with a grinding wheel as the said work is simultaneously moved longitudinally through a path defined by the line contact of the said follower finger with the profiled dummy. All of which is more particularly described and ascertained hereinafter, by way of ex- Figure 3 is an end elevation ofthe device.

Similar, characters of reference indicate similar parts in the several figures of the drawings.

l0 indicates the base structure of a grinding machine on which the longitudinal movable table H is mounted, which table II in turn carries the transversely slidable table 12. The base structure H1 is provided with upwardly extending arms l3 and 14 supporting a rider bar l5 which extends across and above the transversely sliding table l2. It represents a grinding wheel which is supported and driven in any well known manner (not shown) and with respect to which the said table I 2 is longitudinally movable together with the table II and transversely movable upon the said table H. v I 41 and I8 are tailstocks mounted on the said table I2, 19 and 20 being centers mounted 'inthe said tailstocks to receive the work 2| therebetween, and 22 and 23 are similar centers carried by the said tailstocks in parallel relation tothe said centers [9 and 20 to receive a dummy 24 I having a, profile which is that of the envelope of the cutting surface of the work 2| to be operated on by the grinding wheel, said dummy 24 acting as a profiled stop for the transversely slidable table l2 as will be further explained.

The rider bar I5 is provided with a normally fixed but adjustable bracket 25 carrying a follower finger 26 which finger is intended to impinge against the profiled surface of the dummy or stop 24 under the influence of a weighted lever 21 linked to the back of the said transversely slidable table l2 and thus biasing the said table l2 in the direction of the grinding wheel. This lever 21 will also operate as a handle, by the manual raising ofwhich the said table l2 may be moved away from the grinding wheel. It will be obvious that such movements of the table accompany corresponding lateral movement of the dummy or stop I 24 relative to the fixed follower finger 26, and it will also be obvious that, if the said table l2 on its table ll be moved longitudinally so that the profiled dummy or stop 24 is traversed relatively by the follower finger 26, the said table will be caused to recede from the grinding wheel as the diameter of the stop 24 increases. This, longitudinal movement of the said table I2 and its acoaeoa Y Q dummy or its sto'p l l relativeto the said follower finger will be accompanied by the lateral sliding of the said table )2 in accordance with variaitions, in diameter of thje said stop 2 and these I movements will produce a resultant path of travel which is thatof the contour of the line on the dummy. any surface or which presented to the :rollower finger will-provide a lineof contact of therequired profile so that the setting up or the 7 work for the chip breaker grinding is of the very simplest nature, the work and its correspondin cylindricalfdummy being simply slipped into posaid stop -24 traversed by the follower finger'; 26.

This path of travel is or" course transmitted to V the work- 2! asthe said work is mountedonthe same table.

the synchronized rotation of the work in order that the said grinding wheel may pass over a helical path about the envelope of the work'a'nd thereby notch the teeth thereof at spaced intervals as indicated at 21, I provide a hand operated feed screw 28 which is shown as being mounted in bearings 29 and 30 carried by the tailstocks I1 and I8 respectively. This feed screw is provided with a ,hand wheel 31 for its manual operation and is threaded through a lead screw follower 32 which in turn is connected by the'swingable link 33 and link pivot clamp 34 to the fixed rider barl5.-

IBy reason of the linkage referred to rotation ofithe feed screw 28 in one or other direction will naturally result inthe longitudinal movement of the table l2 with its supporting table II, and this movement will in turn result in the sliding table [2 moving transversely of the table H by virtue of the action of a profiled stop 24 on the follower finger 26 as previously described;

To effect rotation of the Work while this move; ment of the table is'being effected I provide interchangeable gears 35 and 36 removably mounted on the shaft of the feed screw 28 and the shank of the work 2 I, and so proportioned that the speed 7 of rotation of the work in relation to the longitudinal movement in front of the grinding wheel will produce the desired helical path of the grinding wheel on the envelope surface of the Work and thereby enable the said grinding wheel to produce the spacedchip breaker notches in the teeth of the'work as clearly indicated in Figure 1 of the drawings.

The provision of chip breaker interruptions in the teeth of rotary form and similar tools is, of course, not new in-itself, it having been a quite ccmmon'practice to do this, and the present invention lies in the simple expedients adopted by which the grinding of such interruptions may be simply and efiectively accomplished on a form tool of varying profile such, for example, as that illustrated in the drawings; and a further imortant feature of the invention resides in the use, in the manner described, of a cylindrical To eflect the foregoing controlled movementoi the work relative to the grinding wheel, and also 'sition between their respectivecenters and the follower finger and the wheel adjusted into required contact with the surface of the dummy or stop and the tooth of the work.

This invention may be developed within the scope of the following claims without departing from the essential features of the said invention, and it is desired that the specification and drawings be read asbeing merely illustrative of a practical embodiment of the said invention and not in a strictly limiting sense.

What I claim is:

1. In a device of the class described, in combination, a fixture table having longitudinally and transversely guided'support a pair of work- I holding centers mounted on said table, a second pair of centers also-mounted on said table in parallel with said work-holding centers,a profiled stop carried by said second pair'of centers,

' a fixed follower finger, means biasing said table to urge said stop against said finger, a feed screw carried by said table, a feed nut on said screw transversely guided support a pairof work-holdmg centers mounted on said table, a second pair of centers also mounted on said table in arallel with said work-holding centers, a profiled stop carried by said second pair of centers, a fixed follower finger, means biasing said table to urge said stop against said finger, afeed screw carried by said table, a feed nut on said screw linked to'said follower finger for moving said table longitudinal- 1y and to cause said stop to also move said table transversely by virtue of the riding of said stop over said finger, interchangeable gears transmitting rotary motion of said feed screw to the work during such combined movements, and a grinding wheel positioned to cutting interruptions in the teeth of said work during the resulting lineal and rotary movements thereof.

' WALTER F. ROSS. 

